反应详情

DCC (2.16 g, 0.011 mol), a catalytic amount of DMAP (0.098 g, 8 mmol) and 1-(tert-butoxycarbonyl)piperidine-4-carboxylic acid (2.04 g, 0.009 mol) were added to a solution of 6,7-Dimethoxy-1,2,3,4-tetrahydroisoquinoline (1.31 g, 0.008 mol) in dichloromethane (30 ml). The clear solution soon deposited a white solid corresponding to the cyclohexyl urea formation. The crude was stirred for 2 hours at room temperature. The solid was filtered and the crude was washed with water and dried over Na2SO4. The solvent was vacuum concentrated and the residue was purified by flash chromatography using a gradient consisting of different mixtures of dichloromethane/methanol to give pure tert-Butyl-4-(6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline-2-carbonyl)piperidine-1-carboxylate as yellow solid (3.8 g, 85% yield).

1. filtrationThe solid was filtered
2. washthe crude was washed with water
3. dry with materialdried over Na2SO4
4. concentrationconcentrated
5. customthe residue was purified by flash chromatography